1 #ifdef USE_PRAGMA_IDENT_HDR
   2 #pragma ident "@(#)instanceRefKlass.hpp 1.62 07/05/29 09:44:21 JVM"
   3 #endif
   4 /*
   5  * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This code is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 only, as
  10  * published by the Free Software Foundation.
  11  *
  12  * This code is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * version 2 for more details (a copy is included in the LICENSE file that
  16  * accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License version
  19  * 2 along with this work; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *  
  26  */
  27 
  28 // An instanceRefKlass is a specialized instanceKlass for Java 
  29 // classes that are subclasses of java/lang/ref/Reference.
  30 //
  31 // These classes are used to implement soft/weak/final/phantom 
  32 // references and finalization, and need special treatment by the
  33 // garbage collector.
  34 //
  35 // During GC discovered reference objects are added (chained) to one
  36 // of the four lists below, depending on the type of reference.
  37 // The linked occurs through the next field in class java/lang/ref/Reference.
  38 //
  39 // Afterwards, the discovered references are processed in decreasing
  40 // order of reachability. Reference objects eligible for notification
  41 // are linked to the static pending_list in class java/lang/ref/Reference,
  42 // and the pending list lock object in the same class is notified.
  43 
  44 
  45 class instanceRefKlass: public instanceKlass {
  46  public:
  47   // Type testing
  48   bool oop_is_instanceRef() const             { return true; }
  49 
  50   // Casting from klassOop
  51   static instanceRefKlass* cast(klassOop k) {
  52     assert(k->klass_part()->oop_is_instanceRef(), "cast to instanceRefKlass");
  53     return (instanceRefKlass*) k->klass_part(); 
  54   }
  55 
  56   // allocation
  57   DEFINE_ALLOCATE_PERMANENT(instanceRefKlass);
  58 
  59   // Garbage collection
  60   int  oop_adjust_pointers(oop obj);
  61   void oop_follow_contents(oop obj);
  62 
  63   // Parallel Scavenge and Parallel Old
  64   PARALLEL_GC_DECLS
  65 
  66   int oop_oop_iterate(oop obj, OopClosure* blk) {
  67     return oop_oop_iterate_v(obj, blk);
  68   }
  69   int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
  70     return oop_oop_iterate_v_m(obj, blk, mr);
  71   }
  72 
  73 #define InstanceRefKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix)                \
  74   int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk);                         \
  75   int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);
  76 
  77   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
  78   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DECL)
  79 
  80 #ifndef SERIALGC
  81 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix)      \
  82   int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
  83 
  84   ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
  85   ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
  86 #endif // !SERIALGC
  87 
  88   static void release_and_notify_pending_list_lock(BasicLock *pending_list_basic_lock);
  89   static void acquire_pending_list_lock(BasicLock *pending_list_basic_lock);
  90 
  91   // Update non-static oop maps so 'referent', 'nextPending' and
  92   // 'discovered' will look like non-oops
  93   static void update_nonstatic_oop_maps(klassOop k);
  94 
  95  public:
  96   // Verification
  97   void oop_verify_on(oop obj, outputStream* st);
  98 };